Future Forests Research Update: Groundbreaking Work to Map Wood Quality in Trees

Predicting product quality in forests is very important for forest owners and managers who want to make forest investment decisions, plan future wood flows, and value forests. A good understanding of the distribution ( or "map") of the varying wood quality features - for example stiffness, shrinkage and resin content - throughout the entire stem of the tree is a prerequisite to predicting product quality.

In the FFR Radiata theme, a ground breaking and innovative project to develop wood quality "maps" for individual trees in a cost efficient manner is being undertaken by a team at Scion. Previous methods of destructive sampling to assess individual tree wood quality features have cost tens of thousands of dollars per tree, making it impossible to sample more than a few trees. The goal of this project is to find a way of significantly reducing the cost of tree sampling to a few hundred dollars per tree, enabling many more combinations of site, genetics, and management to be assessed for their impact on wood quality.

The methodology involves dicing trees into 30mm discs from butt to around 30m, imaging every disc using a colour camera and then selecting a set of clear discs at approximately one metre spacing for further intensive measurement. Discs from this subset are then assessed for the four key features contributing to wood quality - micro fibril angle, chemical composition, density and grain orientation. Advanced imaging techniques including ultrasonic velocity, near infrared spectroscopy, x-ray radiography, and transmitted light are being used to assess each disc and from this a map of wood quality distribution throughout the stem can be constructed.

The initial focus has been on reducing the costs of sectioning the stem into discs. Initial trials with a Waratah processor head were unsuccessful and current efforts are focused on a cut off saw on a horizontal conveyor system. With the assistance of Ian Piebenga and staff at PermaPine, the latest methodology will be tested in February 2011. Once this is proven, the focus will move to developing a cost effective means of imaging and assessing the wood quality in each disk.

Cut off saw sectioning stem into 30mm discs

Sectioned disc scanned using colour and X-Ray imagery

Scanning disc using Near Infrared (NIR) Robot